This invention pertains to electro-acoustical devices.
U.S. Pat. No. 4,028,491, issued June 7, 1977 to the same assignee, discloses a transducer switching system that serves the same purpose as the present invention.
However, it has been found that the slotted poppet type valve of the above patent is subject to audio loss out the rear chamber. Once the valve opens it allows any accumulated particles and/or liquids to directly enter the electrical contact area. The slotted valve can be easily damaged by the blade of a screwdriver, or similar object, being inserted into the open cavity, engaged in the slot and rotated; inadvertently by a service man, or otherwise. This breaks the valve and prevents it from ever being used again for its intended purpose.
The switch contact, being a double-wound spring, has had variations in the actuation point as the headset plug was inserted normally into the open cavity. The spring contact makes a butt type electrical connection and is not self-cleaning.
U.S. Pat. No. 3,610,830, Daleiden, discloses a switch 39 that is operated by translation of sleeve 34A when plug 14A is inserted. However, switch 39 makes butt electrical and mechanical contact, and is devoid of any self-cleaning wiping action.